Voyager 1: The Little Spacecraft That Could

He found that in the late 1970s and early 1980s, Jupiter, Saturn, Uranus, Neptune, and Pluto would be at the right relative positions in their orbits that a spacecraft could visit each of them on a grand tour. The secret was gravity assists, using the planets’ gravity to slingshot the spacecraft from one to the next.

To take advantage of the opportunity, NASA developed the twin Voyager spacecraft. Both would fly by Jupiter and Saturn, adding valuable scientific data to what was then a very scant knowledge of the outer solar system. Ground-based studies revealed the planets’ most basic properties, and hinted that there were fascinating discoveries still to make.